CONICET | Buscador de Institutos y Recursos Humanos

In this comment we analyze the improved series proposed by Duki et al (2018Eur. J. Phys. 3 9 065802) for the approximate calculation of a variety of physical quantities like the period of the simple pendulum and an integral of theexponential of a two-dimensional potential-energy function. We show that theapplication of the approach to the latter case is unnecessary because both theexpansion coeffiients and the original problem are given in terms of a similar error function. Present results for the straightforward expansion with exactanalytic coeffiients do not show the oscillatory behaviour exhibited by the calculations of those authors. We give reasons why the improved approach of Dukiet al may not be suitable for the treatment of many realistic physical problems.